One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,6,4)(3,8,5,7)(9,10)(11,17)(12,14)(13,20)(15,19)(16,22)(18,23)(21,24)(26,31)(27,33)(29,37)(36,39)(10,12)(15,17)(16,20)(23,24)(25,26)(27,32)(28,33)(29,34)(30,31)(35,39)(36,40)(37,38) involution — undirected(1,3,6,5)(2,7,4,8)(9,11)(10,15)(12,17)(13,18)(14,19)(16,23)(20,24)(21,22)(25,27)(26,28)(29,35)(30,33)(31,32)(34,36)(37,40)(38,39)(1,3,6,5)(2,8,4,7)(9,11)(10,15)(12,17)(13,21)(14,19)(16,24)(18,22)(20,23)(25,27)(26,32)(28,31)(29,35)(30,33)(34,39)(36,38)(37,40)(1,4,6,2)(3,8,5,7)(9,12,14,10)(11,17,19,15)(13,20,22,16)(18,24,21,23)(25,28,30,32)(26,33,31,27)(29,36,37,39)(34,40,38,35)(1,5,6,3)(2,8,4,7)(9,13)(10,16)(11,18)(12,20)(14,22)(15,23)(17,24)(19,21)(25,29)(26,34)(27,35)(28,36)(30,37)(31,38)(32,39)(33,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.